Spaces:
Running
Running
| """Compute the cosine similarity matrix of A. | |
| https://stackoverflow.com/questions/17627219/whats-the-fastest-way-in-python-to-calculate-cosine-similarity-given-sparse-mat | |
| """ | |
| from typing import Optional | |
| import numpy as np | |
| def cos_matrix2(mat1: np.ndarray, mat2: Optional[np.ndarray] = None) -> np.ndarray: | |
| """Compute the cosine similarity matrix of mat1, mat2: mat1 * mat2.T. | |
| Args: | |
| mat1: np.asarray | |
| mat2: [Optional], if not present mat2 = mat1 | |
| Returns | |
| cosine similarity | |
| """ | |
| if not isinstance(mat1, np.ndarray): | |
| mat1 = np.asarray(mat1, dtype=np.float32) | |
| if mat2 is None: | |
| mat2 = mat1.copy() | |
| if not isinstance(mat2, np.ndarray): | |
| mat2 = np.asarray(mat2, dtype=np.float32) | |
| if mat1.shape[1] != mat2.shape[1]: | |
| print("shape mismatch: %s, %s", mat1.shape, mat2.shape) | |
| raise SystemError(1) | |
| cosine = np.dot(mat1, mat2.T) | |
| norm1 = np.linalg.norm(mat1, axis=1) | |
| norm2 = np.linalg.norm(mat2, axis=1) | |
| # if not (norm1 and norm2): return 0 | |
| size1 = norm1.size | |
| size2 = norm2.size | |
| norm_mat = np.dot(norm1.reshape(size1, 1), norm2.reshape(1, size2)) | |
| for idx in range(size1): | |
| for jdx in range(size2): | |
| if norm_mat[idx, jdx] == 0: | |
| cosine[idx, jdx] = 0.0 | |
| else: | |
| cosine[idx, jdx] = cosine[idx, jdx] / norm_mat[idx, jdx] | |
| return cosine | |